The mobile device management (MDM) APIs in iOS 5 have been updated so that MDM tools from, say, MobileIron will be able to turn off iCloud syncing, require the use of a password to access iTunes, disable email forwarding, delete -- not just render inaccessible -- apps (both individually and for all corporate-provisioned apps), disable voice and data roaming, set policies for the handling of nontrusted certificates, detect and reapply user-deleted MDM configuration profiles, set Web proxies, set autologin for approved Wi-Fi access points, send crash data, and monitor battery levels.

The mobile Safari browser on the iPad now uses tabbed panes, and it brings in the Reading List and Reader capabilities from the desktop Safari browser.

iOS 5 adds support for private browsing to Safari, so your history is not retained if you enable this feature in the Settings app.

Communications and collaboration changes

Tweeting is now available as an option from the Share menu in most apps, along with the previous options to email and print. But you have to install the free Twitter app to get this feature.

The Mail app adds message flagging, the ability for users to delete and add mail folders, and the ability to apply rich text formatting to messages. It also now supports the S/MIME secure messaging protocol.

The Messages app is no longer an iPhone-only app, adding iOS-only messaging service called iMessage for all iOS devices à la Research in Motion's BlackBerry Messenger (in addition to SMS on the iPhone).

The Calendar app gets a year view that includes a heat map of your busiest days, you can now specify the time zone individually in calendar entries, and you can now set a default alert time for new entries.

The new Reminders app provides a single location for managing your to-do items; it syncs with Exchange, IMAP, and local (via iCloud) task lists.

Entertainment and photography changes

The Newsstand app -- really a special folder -- contains periodicals you've bought via iTunes -- a new type of content you can buy there individually or via subscriptions.

The iPod app has been renamed Music, so there's now a consistent name across all iOS devices for that app. And the app's UI has changed dramatically, with a sparer design -- the capabilities remain the same, though.

Your music -- not just what you bought on iTunes -- can be stored in the cloud for access when needed from all devices attached to your Apple ID; this iTunes Match service costs $25 per year. Music you bought via iTunes is synced to all your devices whether or not you use iTunes Match.

The Camera app now provides red-eye removal, cropping, rotation, and straightening capabilities for photos you take or bring onto an iOS 5 device.

The Photos app now lets you create your own albums, as well as wirelessly sync photos to other iOS devices, Macs, and Windows PCs via the Photo Streaming service in iCloud.

Galen Gruman is an executive editor at InfoWorld focused on mobile and user-facing technologies, an author of more than 40 how-to books, editorial CTO for IDG US Media (InfoWorld's parent company), and an adjunct analyst focused on enterprise mobility at IDC's IT Executive Program.